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|Section2= |Section7= }} Aspartame (APM; or ) is an artificial, non-saccharide sweetener used as a sugar substitute in some foods and beverages. In the European Union, it is codified as E951. Aspartame is a methyl ester of the aspartic acid/phenylalanine dipeptide. It was first sold under the brand name NutraSweet. It was first synthesized in 1965, and the patent expired in 1992. The safety of aspartame has been the subject of several political and medical controversies, United States congressional hearings and Internet hoaxes〔(Aspartame ) on Snopes.com〕〔(ACSH Debunks Internet Health Hoax )〕〔(A Web of Deceit )〕 since its initial approval for use in food products by the U.S. Food and Drug Administration (FDA) in 1981.〔 The European Food Safety Authority concluded in its 2013 re-evaluation that aspartame and its breakdown products are safe for human consumption at current levels of exposure, corroborating other medical reviews. However, because its breakdown products include phenylalanine, aspartame must be avoided by people with the genetic condition phenylketonuria (PKU). ==Chemistry== Aspartame is a methyl ester of the dipeptide of the natural amino acids L-aspartic acid and L-phenylalanine. Under strongly acidic or alkaline conditions, aspartame may generate methanol by hydrolysis. Under more severe conditions, the peptide bonds are also hydrolyzed, resulting in free amino acids.〔 〕 While known aspects of synthesis are covered by patents, many details are proprietary. Two approaches to synthesis are used commercially. In the chemical synthesis, the two carboxyl groups of aspartic acid are joined into an anhydride, and the amino group is protected by a compound that will prevent further reactions of that group. Phenylalanine is methylated and combined with the ''N''-protected aspartic anhydride; then the blocking group is removed from aspartic acid by acid hydrolysis. The drawback of this technique is that a byproduct, the bitter-tasting β-form, is produced when the wrong carboxyl group from aspartic acid links to phenylalanine. A process using an enzyme from ''Bacillus thermoproteolyticus'' to catalyze the condensation of the chemically altered amino acids will produce high yields without the β-form byproduct. A variant of this method, which has not been used commercially, uses unmodified aspartic acid, but produces low yields. Methods for directly producing aspartyl-phenylalanine by enzymatic means, followed by chemical methylation, have also been tried, but not scaled for industrial production. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Aspartame」の詳細全文を読む スポンサード リンク
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